Radio communication systems have been traditionally proprietary in nature, typically involving a single manufacturer, or a limited set of manufacturers, that provide infrastructure and other communication equipment. Recently, there has been a move toward more open systems in which multiple manufacturers provide various components of the communication system. In an open communications system, heterogeneous communication equipment must be interoperable to be effective. To facilitate such interoperability, standards are usually established and promoted which govern interface specifications, communication protocol, and the like. Strict adherence to such standards are ordinarily necessary in order to effectively operate an open communication system.
Standards are established in a variety of ways. For example, a de facto standard may be established by long-standing practice, or by the practices of a dominant market player. More recently, there has been a trend toward standards establishing bodies, which may comprise government regulators and industry participants. A standard once established reflects compromises with respect to the state of technology. Various standards have been developed, and others are under consideration for two way radio communications systems. One well known prior art standard is the global system for mobile communication (GSM) standard for mobile phones. Benefits of such standards include the potential of lower cost to consumers from wider participation of various vendors, and wider availability of options.
In wireless radio frequency (RF) communication applications, one desirable standard is that of channel modulation. A channel modulation standard enables heterogeneous communication equipment to participate in radio communications. Once a particular channel modulation technique is chosen, this necessarily affects channel bandwidth, and consequently the quantity of information that may be transmitted over a given communication channel. Depending on the application, tradeoffs are often necessary when apportioning the channel bandwidth among data, error protection information, control information, and the like. For example, some applications, such as voice communication, may be real time in nature and therefore have different requirements than data communication that is not real time. Consequently, a channel modulation scheme is usually selected after evaluation of suitability for the information likely to be trafficked across a communication channel. Once a modulation scheme is selected and accepted as a standard, communication equipment participating in the radio communications system must adhere to the standard in order to maintain compatibility. This impacts the ability to provide enhanced communication capabilities through an increase in bandwidth, or other manipulation of communication parameters.
While standards provide substantial benefits to the consumer through lower cost and greater options, standards inherently reflect compromises in technology. For specific applications, the established standards might not directly support certain performance needs. Notably, a standard channel modulation scheme has a tendency to fix channel bandwidth which limits the opportunities to use additional information to improve communication. Yet, it is the standard channel modulation scheme that enables heterogeneous communication equipment to operate compatibly. Accordingly, it is desirable to provide a method and apparatus for enhanced communication capability while maintaining standard channel modulation compatibility.